DIFFERENT SUSCEPTIBILITY TO THE IL-3 INDUCED-PROTECTIVE EFFECTS BETWEEN STRONGYLOIDES-RATTI AND NIPPOSTRONGYLUS-BRASILIENSIS IN C57BL 6 MICE/

Repetitive administration of recombinant IL-3 induced protection again st Strongyloides ratti but not against Nippostrongylus brasiliensis in C57BL/6 mice. Numbers of S. ratti were negligible from day 4 to day 6 post-infection in mice injected with IL-3, whereas N. brasiliensis bu rdens were almost equal from day 4 to day 6 between mice injected with IL-3 or with medium. Mice treated with IL-3 and then concurrently inf ected with S. ratti and N. brasiliensis were protected from intestinal S. ratti but not from N. brasiliensis. The numbers of intestinal muco sal mast cells were increased by the repetitive IL-3 treatment on one day after the final injection and was augmented by subsequent infectio n with both nematodes.